From 2822545f9fe264ec62d4abc69c17ae759eafe4ce Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 15 Oct 2014 16:48:16 +0200 Subject: KVM: s390: new parameter for SIGP STOP irqs In order to get rid of the action_flags and to properly migrate pending SIGP STOP irqs triggered e.g. by SIGP STOP AND STORE STATUS, we need to remember whether to store the status when stopping. For this reason, a new parameter (flags) for the SIGP STOP irq is introduced. These flags further define details of the requested STOP and can be easily migrated. Reviewed-by: Thomas Huth Acked-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/api.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/virtual/kvm/api.txt') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0007fef4ed81..3ca6e0e9a769 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2312,7 +2312,7 @@ struct kvm_s390_interrupt { type can be one of the following: -KVM_S390_SIGP_STOP (vcpu) - sigp restart +KVM_S390_SIGP_STOP (vcpu) - sigp stop; optional flags in parm KVM_S390_PROGRAM_INT (vcpu) - program check; code in parm KVM_S390_SIGP_SET_PREFIX (vcpu) - sigp set prefix; prefix address in parm KVM_S390_RESTART (vcpu) - restart -- cgit v1.2.1 From 2444b352c3acf54897b0e2803a7c4e66699f9f43 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 9 Oct 2014 14:10:13 +0200 Subject: KVM: s390: forward most SIGP orders to user space Most SIGP orders are handled partially in kernel and partially in user space. In order to: - Get a correct SIGP SET PREFIX handler that informs user space - Avoid race conditions between concurrently executed SIGP orders - Serialize SIGP orders per VCPU We need to handle all "slow" SIGP orders in user space. The remaining ones to be handled completely in kernel are: - SENSE - SENSE RUNNING - EXTERNAL CALL - EMERGENCY SIGNAL - CONDITIONAL EMERGENCY SIGNAL According to the PoP, they have to be fast. They can be executed without conflicting to the actions of other pending/concurrently executing orders (e.g. STOP vs. START). This patch introduces a new capability that will - when enabled - forward all but the mentioned SIGP orders to user space. The instruction counters in the kernel are still updated. Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/api.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'Documentation/virtual/kvm/api.txt') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 3ca6e0e9a769..df19837e94d4 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3225,3 +3225,23 @@ userspace from doing that. If the hcall number specified is not one that has an in-kernel implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL error. + +7.2 KVM_CAP_S390_USER_SIGP + +Architectures: s390 +Parameters: none + +This capability controls which SIGP orders will be handled completely in user +space. With this capability enabled, all fast orders will be handled completely +in the kernel: +- SENSE +- SENSE RUNNING +- EXTERNAL CALL +- EMERGENCY SIGNAL +- CONDITIONAL EMERGENCY SIGNAL + +All other orders will be handled completely in user space. + +Only privileged operation exceptions will be checked for in the kernel (or even +in the hardware prior to interception). If this capability is not enabled, the +old way of handling SIGP orders is used (partially in kernel and user space). -- cgit v1.2.1